This application is based on European Patent Application No. 00830053.5 filed on Jan. 28, 2000, the content of which is incorporated hereinto by reference.
I. Field of the Invention
The present invention relates to a device for removing dust and rubbish from a surface, for example a fabric surface, such as a moquette, carpet and the like, or from a bare surface, such as a tiled, marble, wooden (parquet) and similar type of floor.
II. Related Art and Other Considerations
Conventional devices for removing dust and rubbish, provided with a turbo-brush head which may be replaced by a simple suction head, are known. In most cases the former is used to clean fabric surfaces, while the latter is used to clean bare surfaces.
Generally, the turbo-brush head includes a rotating brush provided with bristles and actuated by a turbine with radial vanes. The rotating brush and the turbine are rotatably supported in two housings inside a casing. The casing has a suction opening, inside which the rotating brush is placed, and a suction nozzle located between the rotating brush and the turbine. A suction pipe connected to a suction device communicates with the suction nozzle and the turbine housing.
When the suction device is in operation, an air flow passes through the suction opening, the nozzle and the suction pipe and strikes the vanes of the turbine, causing the latter to rotate. The turbine transmits the rotary movement to the brush via a toothed belt, and the brush, rotating, with its bristles passes over the surface to be cleaned (fabric surface, which may be padded, tapestry, furnishing, moquette, carpet and the like), removing the dust and the rubbish which are sucked up by the air flow generated by the suction device.
The simple suction head, in turn, includes its own suction opening which is placed in communication with the suction pipe connected to the suction device.
JP-06098840 discloses a vacuum cleaner having a suction air flow which is turned into a jet flow after passing through a nozzle to rotate an impeller and then it is turned into an exhaust air flow. Rotation of the impeller of the turbine rotates a rotary brush through a timing belt. A main nozzle and a bypass nozzle are positioned on a nozzle supporting plate and the cross-sectional shape of the nozzle is made into a circular form or an elliptic form. A plate shutter is engageable with the bypass nozzle to close it. The main nozzle is used for a heavy loading such as a carpet and the bypass nozzle is used for a relatively light loading such as a tatami mat or a wooden flooring.
The circular or elliptic form of the nozzle has the purpose of decreasing the sound of the air flow.
In said vacuum cleaner, the air flows coming from both the main and bypass nozzles enter the turbine housing.
The turbine and the rotary brush are always active, since the steps of opening and closing the bypass nozzle have only the aim of adjusting the air flow directed on the turbine.
Therefore, said vacuum cleaner always operates as a turbo-brush head and never can operate only as a suction head.
As far as the inventors are aware, hitherto a commercial device which is capable of operating both as a turbo-brush head and as a simple suction head has not yet been developed.
The object of the present invention is to provide a device which is capable of performing both the functions and which is easy and inexpensive to manufacture.
A device for removing dust and rubbish from a surface comprises a casing provided with a suction opening, a rotating brush, and a turbine operationally connected to the brush, a suction nozzle having a predefined flow cross-section, and a suction pipe connected to a suction device. The rotating brush has a shaft rotatably supported in a first housing of the casing; the turbine has a shaft rotatably supported in a second housing of said casing. The suction nozzle is located between the rotating brush and the turbine for directing an air flow from the suction opening onto the rotating brush and then towards the turbine. The device also includes a bypass duct and a first valve, the bypass duct having a predefined flow cross-section and being designed for bypassing the second housing and the turbine, and for connecting the suction opening and the first housing with the suction pipe and the suction device. The first valve is able to engage the suction nozzle and the bypass duct for closing the suction nozzle and opening the bypass duct.
Opening of the bypass duct, together with the simultaneous closing of the suction nozzle, deactivates the turbine and the rotating brush and causes the device to operate as a suction head only. In turn, opening of the suction nozzle, together with simultaneous closing of the bypass duct, activates the turbine and the rotating brush and causes the device to operate as a turbo-brush head.
Preferably, said first valve is able to vary gradually the flow cross-section of the suction nozzle.
Advantageously, the first valve is able to vary gradually the flow cross-section of the at least a bypass duct.
In particular, the first valve is able to close gradually the flow cross-section of the suction nozzle, while the first valve gradually opens the flow cross-section of the bypass duct.
Advantageously, the first valve is connected to a manual actuating element.
Preferably, the first valve comprises a first slide valve having a first sliding shutter provided with a first opening able to be superimposed on the flow cross-section of the suction nozzle.
In an embodiment, the first sliding shutter is further provided with a second opening able to be superimposed on the flow cross-section of the bypass duct.
Preferably, the first and second opening of the first sliding shutter have a width greater than the width of the flow cross-section of the suction nozzle and, respectively, of the flow cross-section of the bypass duct.
Advantageously, the device also includes an auxiliary opening which connects the first housing to the external environment and a second valve able to engage with the auxiliary opening for opening it when the turbine undergoes a drop in power owing to obstruction of the suction opening, for example by a moquette or a carpet.
Preferably, the second valve comprises a second slide valve having a second sliding shutter provided with a third opening designed to be superimposed on the auxiliary opening.
Advantageously, the first and second sliding shutter are operationally connected to a slider actuator.
Typically, the shaft of the rotating brush is also movably supported in the first housing and is operationally connected to actuating means capable of raising it and keeping it raised so as to move said rotating brush away from the surface to be cleaned.
Preferably, the actuating means includes two levers which rotatably support the shaft of the rotating brush. The two levers are pivotably mounted in the first housing.
Advantageously, the actuating means also includes a projecting element integral with the levers, the first sliding shutter being provided with a ramp and a surface which engage with the projecting element, raising it and causing it to rotate integrally with the levers for raising the rotating brush and keeping it raised.
Preferably, the first opening of the first sliding shutter is able to be superimposed on the the flow cross-section of said suction nozzle and/or on the flow cross-section of the bypass duct.
Typically, the first opening of the first shutter has a width greater than the width of the flow cross-section of the suction nozzle and substantially equal to the width of the flow cross-section of the bypass duct.
In an embodiment, the bypass duct is placed under the second housing.
In another embodiment, a first bypass duct and a second bypass duct are placed at the sides of the second housing.
Preferably, the first sliding shutter is provided with a lateral portion able to be superimposed on the flow cross-section of the second bypass duct, while the first opening is able to be superimposed on the flow cross-section of the suction nozzle and/or on the flow cross-section of the first bypass duct.
As already indicated, the device according to the invention offers the advantage that it may be used both as a turbo-brush head for cleaning a moquette, a carpet and the like, and as a simple suction head for cleaning a bare surface.
In order to vary the operating mode of the device from a turbo-brush head to a simple suction head, it is simply required to actuate manually the first valve so that it closes the nozzle which conveys the sucked-in air flow towards the turbine and, at the same time, open the turbine bypass duct. As a result, the turbine is deactivated and ceases to actuate the rotating brush, while the air which enters via the suction opening flows directly into the suction pipe connected to the suction device. When the operating mode as a simple suction head is selected, it is also possible to raise the rotating brush from the surface to be cleaned so that it does not hinder in any way suction of the dust and rubbish.
In addition, when the operating mode as a turbo-brush head is selected and the rotating brush encounters a strong resistance and tends to stop rotating, it is possible to activate an auxiliary opening which allows the entry of an additional air flow directed towards the turbine which thus starts to rotate again and reactivates the rotating brush.
The device is particularly efficient because the exclusion of the turbine from the path of the air which flows from the suction opening to the suction device does not produce that dispersion of energy which occurs when the sucked air flow interacts with the turbine.